Protective cover for an aerial missile



March 12, 1963 R. o. ROBINSON, JR., ETAL 3,080,817

PROTECTIVE COVER FOR AN AERIAL MISSILE Original Filed Feb. 12. 1959 INVENTORS RALPH 0. ROBINSON, JR. THOMAS M. SHEPPARD ATTORNEY missile nose probe;

3 Claims. 01. 102-425 The present invention relates generally to protective devices for aerial vehicles; more particularly it relates to improved displaceable seals for use with pressure probes or radomes'of guided missiles.

This application is a division of US. patent application Serial No. 792,936, filed February 12, 1959, now Patent No. 2,987,999, issued June 13, 1961, by the present applicants.

Guided missiles require information regarding-static pressures and/or ram pressures in order to maneuver properly. Such missiles ordinarily employ pressure probes and/or radornes having ports connected with appropriate equipment for measuring such static or ram pressures. It is important that these ports be kept free of foreign bodies if the measuring equipment is to function properly. That is, during the handling of guided missiles prior to launching thereof they may by subjected to a variety of environmental conditions which would be deleterious to the proper functioning of pressure measuring equipment. Such conditions would include ocean waves, high winds, ice, shock, and vibration. Moreover, since the launching of a guided missile is a complicated operation under optimum conditions, it is desirable that seals be provided that will remain in place during handling and launching operations but which will be removed automatically and positively after the missile has been launched.

The'invention seeks, as object, to provide a displaceable seal which, may be used for closing the port or ports of a missile nose probe until after missile launching.

A further object of the invention is to provide a displaceable seal which employs a low melting pointv alloy for securing said seal in position on a missile nose or nose probe, which alloy may only be melted by thecoincident occurrence of a high velocity air flow and the resultant high sta nation temperature which occurs only during missile flight.

Still another object of the invention resides provision of a displaceable seal which will be characterized by its extreme simplicity and ease of application.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: I

FIG. 1- is 'a side elevation, partly in section, showing an embodiment of the invention, the positions -of the sections of the seal being shown in broken linesas they '1 in the would appear immediately prior to separation from a FIG. 2 is a front elevation-of the embodiment in FIG. 1; and

FIG. 3 is a front elevation showing a modified slot arrangement for use with the embodiment of FIGSVI and 2.

Referring now to the embodiment of the invention shown in FIGS. 1, 2 and 3, the numeral 21 indicates a pressure probe which is mounted on the nose of a missile, a portion of which nose is shown at 22. The probe 21 is formed in its side wall with an inlet port 23. The protective device constituting the embodiment shown in shown 23 within the sections 24 and 3,080,817 Patented Mar. 12, 1963 ice FIGS. 1, 2, and 3 includes a body having semi-cylindrical cooperating sections 24 and 25 which are connected at their rear ends by curved tongue and groove hinge parts or portions defining displaceable hinges 27 and which are formed with flared forward end portions 28 having concentric grooves 29 and 30 in their front or end faces. Inwardly of the forward ends of the sections 24 and 25 are mating recesses 31 which cooperate to define a chamber for receiving a normally compressed helical spring 32. As best seen in FIG. 1, the sections 24 and 25 snugly receive the'forward end of the probe 21 and, effectively seal theopening 23 to prevent the entry of foreign substances into the interior of the probe.

.Normally' retaining the sections 24 and 25' in mating relation, for defining the seal, is a deposit of low melting point alloy 33, such as Cerrobend, produced by the Cerro de Pasco Corporation, New York, New York. The composition of Cerrobend is 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium, and its melting tem-' perature is 158 F. Other propertiesof Cerrobend are as follows:

Approximate specific heat liquid .040

The deposit 3-3 completely fills the grooves 29 and 3d and covers the outer end faces of the sections 24 and 25 for retaining the sections in assembled relation, the hinge 2'7 securing the corresponding rear end portions of the sections 24 and 25 against displacement.

In use, when a missile utilizing the seal constructed as described above is fired, air flow. at high temperature will impinge on the deposit 33 for melting the same, when continuing air flow, accompanicd'by the expanding effort of the spring 32, will urge the sections 24 and 25 outwardly to the positions shown in dotted lines in FIG. 1. Further outward movernent, which will be brought about by the aforementioned air flow, will cause separation of the hinge 27, when the sections 24 and 25 will be blown clear of the missile. Air flow may then enter the opening 23 in the probe 21.

In lieu of the concentric grooves 29 and 30, parallel rectangular grooves may be employed; -such grooves are shown at 34 and .35 in FIG. 3. Also, if desired, supplemental sealing means may be'pl'aced over the opening I 25, as shown in dotted lines at 36 in FIG. 1.

- Obviously many modifications and variations of the presentinvention arepossible in the light of the above teachings. it is therefore to be understood that within a the scope of the appended claims theinvention may be.

practiced otherwise than as specifically described.

' .What is claimed is;

1. In combinationwith 'an aerial missile having a nose probe formed with an opening, a displaceable protective characteristics and disposed on said front. faces and in said grooves in a manner whereby said retaining means will be rendered inoperative to further restrain said sections dueto the melting of said masswhich occurs with the increase in temperature created bythe friction effects of air fiow relative thereto and thereafter allow the force effects of said air flow to separate said sections and to remove thern from the probe 1 2. Incombination with an aerial missile having a nose probe, a displaceable protective device comprising,,a pair of mating semi-cylindrical sections having hinge portions connecting said sections ,at their rear ends, the forward portions of said sections beingfiared and terminating in flat faces having spaced grooves therein, a spring inter- I posed between said mating sections and urging said sections apart, and a retaining means for holding said sections in mating relation comprising a mass of alloy'having low melting point characteristics and'disposed on said faces and in said grooves in a manner whereby said re vt'aining-mean's will be rendered inoperative to restrain said sections due to the melting ofsaid massv which oction efiects of air flow relative thereto and thereafter allow said spring to separate said sections. 7

3. A displaceable protective devicefor protecting nose probe openings in vehicles travelingthrough a fluid mer effects occuring withrnelting of said mass due toatems' dium comprising, a pair of. mating semi-cylindrical sec, tions having hingeportions defining a 'displaceable hinge connectingsaid sections at corresponding rear ends, said sections being in matingrelation and having a blunt end, said end having grooves therein, and amass of alloy having low melting point characteristics disposed on said end and in said grooves in a manner normally retaining said,

sections in mating, relation and whereby the fluid flow peratu-re rise occasioned by air movement relative to said sections willfree said sections for displacement from the probe. 7

v curs with the increase in temperature created by the fric- "20 I References Cited in the file of this patent v t V Y UNITEDSTATES PATENTS 

1. IN COMBINATION WITH AN AERIAL MISSILE HAVING A NOSE PROBE FORMED WITH AN OPENING, A DISPLACEABLE PROTECTIVE DEVICE COMPRISING, A PAIR OF SEMI-CYLINDRICAL SECTIONS FITTING IN MATING RELATION ABOUT THE PROBE, SAID SECTIONS HAVING HINGE PORTIONS AT THEIR REAR ENDS COOPERATING TO DEFINE A SEPARABLE HINGE, AND HAVING FLARED FORWARD END PORTIONS WITH FRONT FACES, COMPLEMENTARY CONCENTRIC SEMICIRCULAR GROOVES IN SAID FACES, AND A RETAINING MEANS FOR HOLDING SAID SECTIONS IN MATING RELATION, SAID MEANS COMPRISING A MASS OF ALLOY POSSESSED OF LOW MELTING POINT CHARACTERISTICS AND DISPOSED ON SAID FRONT FACES AND IN SAID GROOVES IN A MANNER WHEREBY SAID RETAINING MEANS WILL BE RENDERED INOPERATIVE TO FURTHER RESTRAIN SAID SECTIONS DUE TO THE MELTING OF SAID MASS WHICH OCCURS WITH THE INCREASE IN TEMPERATURE CREATED BY THE FRICTION EFFECTS OF AIR FLOW RELATIVE THERETO AND THEREAFTER ALLOW THE FORCE EFFECTS OF SAID AIR FLOW TO SEPARATE SAID SECTIONSS AND TO REMOVE THEM FROM THE PROBE. 